GB1031407A - Improvements in or relating to polyesters - Google Patents

Abstract

A fire-retardant polyester resin is obtained by reacting dicyclopentadiene with the reaction product from (A) one or more dicarboxylic acids and/or ester-forming derivatives thereof, (B) one or more bromine-containing carboxylic acids, (C) one or more condensable phosphorus-containing compounds, and (D) one or more polyhydroxy compounds and/or ester-forming derivatives thereof, at least 20% of the total equivalents of acids and hydroxy compounds containing an olefinic bond, and the bromine and phosphorus together amounting to at least 2 weight per cent. The initial polyester preferably has an acid value of 70-150, falling after reaction with dicyclodiene to below 70, and to at least 20 less than the original value if this was 70-90. Preferably 0.05-0.6 mols. of dicyclopentadiene are used per mol. of dicarboxylic acid. The dicarboxylic acid (A) is preferably an a ,b -unsaturated dicarboxylic acid, e.g. maleic, fumaric, itaconic, mesaconic, or citraconic acids, or anhydrides or half-esters thereof with a polyhydric alcohol, but may contain preferably not more than 60 equivalent per cent of other acids, e.g. succinic, adipic, sebacic, azelaic, the phthalic and di-, tri-, and tetra-chloro phthalic acids, and tetrahydrophthalic acid, and chlorendic acid. Higher polybasic acids may be used in minor amounts, e.g. pyromellitic or trimellitic acid, the additional carboxy group(s) being esterified with monohydric alcohols. The poly-hydroxy compounds (D) may be, e.g. ethylene glycol, diethylene glycol, 1,2- or 1,3-propanediol, 2,2-dialkanepropadiols, 1,3- and 1,4 - butanediols, D 2.3 - butene - 1,4 - diol, 1,6 - hexanediol, dimethylolbenzenes, resorcinol, the 4,41 - dihydroxy - dicyclohexyl alkanes, the 4,41 - dihydroxy - diphenyl alkanes, trimethylolpropane, glycerol monochlorhydrin, pentaerythritol dichlorohydrin, pentachlorophenyl monoglycerol ether, 4,6-dibromo - resorcinol - bis - (b - hydroxyethyl) ether and 2,3 - bis - [dibromo - 4 - (b - hydroxyethoxy)phenyl] propane. Higher polyhydroxy alcohols may be used, e.g. glycerol, trimethylolpropane or -ethane, the additional hydroxy group(s) being etherified or esterified with monofunctional alcohols or acids. The bromine containing acids (B) are preferably polybasic with at least 2 Br atoms in the molecule, e.g. the bromine additions products of maleic, fumaric, itaconic, mesaconic, and citraconic acids, or of acrylic ricinoleic or linseed oil fatty acids, or di- and tetra-bromophthalic acids, hexabromoendomethylenetetrahydrophthalic acid, dibromohexahydrophthalic acid and dibromoendomethylenehexahydrophthalic acid. The phosphorus compounds (C) may be acids, thio acids, amides, organic oxides, sulphides, esters, thioesters and halides, and include phosphoric acid, phosphorous acid, pyrophosphoric acid, the phosphinic acids and the phosphonic acids and esters and halides thereof, and trimethylol phosphine oxide and tetramethylol phosphonium halides, phosphine sulphides, thiophosphites, thio- and dithio-phosphates, phosphonic amides, amido-phosphites and amido-phosphates. The product resins may be copolymerized with e.g. styrene, alkyland chloro-styrenes, a -methylstyrene, vinyl acetate or propionate, acrylic and methacrylic acid esters, allyl acetate or propionate, diallyl maleate, succinate, adipate, azelate, sebacate, or phthalate, triallyl phosphate, diallyl benzenphosphonate, triallyl cyanurate and N-vinylpyrrolidone. The ratio of vinyl compound to polyester may vary from 4:1 to 1:9, by weight. Conventional polymerization inhibitors, catalysts and accelerators may be used, or an accelerator such as aniline- or p-toluidine-N,N-diacetic acid or N,N-bis-(hydroxyethyl)-aniline or -p-toluidine may be incorporated into the polyester. The product polyesters may also be reacted with polyisocyanates, e.g. 4,41 - diphenylmethane -, 1,5 - naphthalene -, 2,21 - diphenyldimethylmethane - 4,41 -, toluylene-2,4 and toluylene-2,6-, and 1,4-cyclohexylene - diisocyanates, and 4,41,411 - triisocyanatophenyl thiophosphate. Fillers, e.g. asbestos, chalk, powdered glass, silicon carbide, sawdust, hardened plastics, calcium hydrogen phosphate, and glass, cotton, polyester or polyamide fibres, dyes and pigments may be incorporated into moulding compositions. In examples, maleic anhydride is condensed with phthalic anhydride (or bis-hydroxyethyl-terephthalate) and dibromosuccinic or dibromoitaconic acids or tetrabromophthalic anhydride or 9,10,12,13,15,16 - hexabromo - octadecanoic acid, and phosphoric acid or 2-hydroxypropane-2-phosphonic acid or a PCl3/ethylene glycol or vinyl phosphonic dichloride/2,2-dimethylpropanediol-1,3 reaction product, and glycerol, trimethylol propane or 2,2-dimethylpropanediol-1,3 in the presence of hydroquinone and triphenyl phosphite, and the product is reacted with dicyclopentadiene. This product in turn may be copolymerized with styrene (70:30 ratio).